Calling Roslyn from Net Framework and Net Core

It never ceases to amaze me how people can write a huge API and never bother to document how to use it. But, it’s been that way for as long as I can remember, going back 35 years. In my latest adventures, I’ve been trying to compile, link, and run C# code dynamically using Roslyn for Piggy, my transformational system. If you’ve ever used Roslyn in C#, you’ve probably discovered that it can be such a pain in the arse to use because Microsoft gives doc for the API, does give some tutorials, but I can’t find a simple example for compiling, linking, and running C#. I don’t need to know all the details yet, just a starting point framework. Unfortunately, the solution is quite sensitive to whether you use Net Core or Net Framework.

After several days of trial and error hacking, I finally wrote a solution to the compile/link/run problem It works with both Net Core and Net Framework. The information is sort of out there (1, 2, 3, 4, and others), but it’s painful reading because it’s inaccurate, and doesn’t always work.

1/2: Adding to #Antlrvsix an analysis tool of #Antlr grammars. This is how it works with cycle detection and useless lexer rules. There are some issues in the responsiveness of the MS LSP client for VS2019.

Adding to #Antlrvsix the refactoring to remove useless parentheses in an #Antlr grammar. This is how it works with the extra parentheses in the arrayAccess_lf_primary rule in Java9.g4 that nobody knew were there. Only yet starting to scratch the surface of grammar optimizations.

Implementing #Antlr grammar fold refactorings in #Antlrvsix. Two types: extract a selected sequence of symbols and make a rule (shown first); replace all occurrences in the grammar with a folded rule (shown second). Spacing and comments do not matter.